Anyone have a copy of the exam?

[WhoTookMyUsername]

For 9d) find the angle between the vector... And the vector r(t) at time zero
Isn't the angle r(t) makes at that point a function of v(t) and not r(t) itself?
Let's say this was your projectile standard question, and it said 'find the angle the position of the particle (r(t)) makes with the i direction' don't you have to find v(t) and then do it?
Im still confused.
Do i have a point or am i just hoping in vain?
If it's the latter could someone point out a flaw in my reasoning?

[BubbleWrapMan]

It says the angle between it and the vector r(t). Doesn't mention the direction of travel, just the vector on its own.

[BubbleWrapMan]

Technically yes, but they'd phrase it as "the angle the plane/object makes with the ground," then you know it's talking about the direction.

[Special At Specialist]

I'm curious how other people worked out question 9d. The only reason I got the answer was because I recognised from doing heaps of textbook questions that (sqrt(6) - sqrt(2)) / 4 was a solution to one of those cos(a + b) angle problems, so I just took a guess, tested out cos(pi/3 + pi/4) and by miracle I got the answer first shot. Will that get me full marks?

[nerfsdacier]

You could also find the angle that each vector makes with the positive x-axis and then add those two angles. But what you did will get you full marks I think, especially since it wasa two mark q.c

[doh07]

I sorta treated the question like a complex number question. found angle of r(0) with positive x-axis, then angle of the other vector, then i subtracted them to get 7pi/12